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Build Log
Pfalz E.1 from Peter Rake plans
As its a bank holiday weekend Im taking the opportunity to get started on the build of my Pfalz E.1. This is a prototype build from Peter Rake's design - 60 inch (1.52m) span for electric power. I think others have built this aeroplane before but at a smaller scale than this one which will be more or less 1/6. I'm building it from scratch so I hope to learn a few new tricks in the process. Peter's design is for a very light model with control on rudder and elevator only and I want to keep to his intentions as close as I can. Hopefully it will look a bit like this photo by the end.
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The fuselage plan is split over two drawings. Peter has also made very useful cutting plans and I am going the low tech route, tracing them with a 6B pencil and then rubbing over this onto the wood, starting with the 5mm ply here. A friend from the field donated an electric scroll saw to me which he wasn't using and this has cut out the bits in no time. I think I will go on and make a 'kit' of parts before doing any gluing.
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Moving on I have now completed the 'kit' of parts. I made a simple jig to make sure the holes for the carbon fibre wing spars were all in the same place and then mounted them on some tubes to sand. I like to start with the tail so thats next up.
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I guess Im a bit slow but I have discovered that the plan at this scale has actually been built several times before - all by great modellers (this is my first time using this forum - I have been using another UK based one in the past where the Pfalz is absent).
https://www.rcgroups.com/forums/show....php?t=1480528 https://www.rcgroups.com/forums/show....php?t=1453808 https://www.rcgroups.com/forums/show....php?t=1278740 So from my reckoning this is at least the fourth build. Well some good help there for me with this one. Any comment on why the plan hasn't made it out of the prototype stage Pete? Im a bit worried that the flying qualities seem to have been cause for concern in the past and would welcome advice from those who have flown it on what I might amend to improve this. Rob |
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This looks like an interesting build. Nice job on your parts!
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Thanks rtibbs - of course you are right - the previous builders used this...
Anyway on with the build. I like to start with the tail. It looked to me like the fin could be made with a single sheet of 3/16 balsa... but its built up to be light and as I want to learn new skills with this one I elected to go with the plan and laminate the external profile. The photo shows my first attempt at this technique. I cut the laminations using my balsa stripper and soaked them for a few hours in warm water. The former was made from two laminations of corrugated cardboard and waterproofed with sellotape. The laminations went quite well round gentle curves but started to crack and split round the tight ones. I just injected more glue and carried on. Not sure how strong it will be when finished but its roughly the right shape! The plan says to use one lamination of bass wood which I didn't have - quite glad didn't as it was hard enough without. Ive also made the tail plane and although I thought some of the small pieces I had made for my kit might be too fragile, once they are in place they seem fine! It went together easy and I remembered to put the hinge tube in before gluing (I used copper tube as I didn't have any aluminium handy). Leave it to dry now and have another go tomorrow (unless its fine in which case I'm off down the field). |
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Pete may still list it as a prototype because none of the previous builders supplied him with pictures of the build for publication. We list them for sale as a prototype first. When one has flown and 'proven' the parts fit then we list it for sale as a regular item.
charlie |
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Laminating was a good idea. The tail on these is a long one and extra weight back there can be a real pain to balance with such a short nose.
When laminating tight curves I will use 1/32" balsa instead of 1/16". I also usually put one or two layers of 1/64 ply strips in the middle to give it some stiffness. To help prevent cracks you can use some blocking around the outside of the curve, and PULL the wet strips around the corners. Sometimes I have done the curving in stages. Bend it a little the first time. Then go back and bend it a second time. charlie |
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Charlie has it precisely, I just never ended up with material to publish. Although from the look of one of them I'm at a loss as to why.
Depending on the prop (if you see my comments about the bigger one) it is a bit squirrelly on the ground, but flies well enough according to most previous builders. I've certainly not had one at any size that was a problem once in the air. It's just a matter of getting the balance right and not having too much elevator throw - and not trying to fly in a lot of wind. Pete |
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Thanks Charlie and Pete - mystery solved. I will try and keep the photos clear on this one in case you want to use it. Here is what has happened with the tail parts which are now pretty much complete. The laminations now fitted with all the other parts seem pretty strong. The outline of the fin is not totally accurate but I doubt it will be obvious once it is covered.
I made an error and glued in the steel rod in the rudder when it should come out to allow the elevator to fit behind... oops! I have tried to pull it out but I will have to destroy the fin to do it so I have a couple of alternate fixes in mind so I'm not too worried. |
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LOL, I did that on my first EIII build as well. I don't remember what I did as a fix. I think I ended up assembling the elevator on the plane so I didn't have to build a second rudder.
charlie |
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It will be something like that Charlie...
Anyway on with the wings. These came together really easily. I used PVA for the wood to wood joints and cyano for the carbon fibre to wood, then backed up with RC Modeller's glue to fill any gaps. The black plastic things are useful little gadgets for making sure the ribs stand at 90˚. Not on this photo but I have subsequently added the small blocks for the rigging. By the way - looking on the other builds no one has really described the rigging. It holds in the wings I think so needs to have some strength - should it be wire or something else? Im working away this weekend so it will be next week before I can do the other wing. |
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I'll be watching this one. Good Luck
Kansas |
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